Pitman rod for windmills



April 26, 1960 B. ISAAC 2,933,950

PITMAN ROD FOR WINDMILLS Filed June 24. 1959 -2 Sheets-Sheet 1 Boyd Isaac l N VE N TOR.

April 26, 1960 ISAAC PITMAN ROD FOR WINDMILLS 2 Sheets-Sheet 2 Filed June 24, 1959 k I wad/ 74% Boyd Isaac j m 7 /m//%/Z 9 2 a 6 3 w n 3 3 2 4 3 2 3 3 w 4 .0 2 5 6 g 3 4 H a 4 6 INVENTOR.

nited States This invention relates to improvements in pitman rods for operatively connecting the wind wheel of a conventional windmill to a pump.

As is well known, such pitman rods frequently break because of overload thereon resulting from failure of the pump often caused by freezing thereof or clogging by sand, or the like.

The primary object of this invention is to provide a pitman rod for windmill operated pumps which cannot break under overload thereon and which is of simple, practical, and economical construction, and safe to use.

To the accomplishment of the above, and other objects presently appearing, the pitman rod of this invention comprises a pair ofupper and lower aligned rod sections adapted to be connected to the wind wheel and pump suction rod respectively, means slidably connecting the 1 rod sections together in alignment so that in case of an overload on the ."pitman rod due to pump failure, the upper section may slide relative to the lower section, whereby to prevent the pitman rod from-breaking, and means for locking the upper and lower rod sections to each other in operating relation and unlocking the same in response to predetermined overload on the pitman rod, all as set forth in the following description, defined in the appended claims, and illustrated in the accompanying drawings in which:

Figure 1 is a view in front elevation of a windmill operated pump embodying the pitman rod of this invention in its preferred form;

Figure 2 is an enlarged fragmentary perspective view of the pitman rod sections, the means for slidably con necting the same, and parts of the locking means;

Figure 3 is a fragmentary enlarged view in vertical atent O section taken on the line 33 of Figure 1 and showing the locking means in locking position;

Figure 4 is a view in horizontal section taken on the line 4-4 of Figure 3;

Figure 5 is an enlarged fragmentary view in vertical section similar to Figure 3 but showing the locking means in unlocking position; f

Figure 6 is a view in horizontalfsection taken on the line 6-6 of Figure 5;

Figure 7 is a fragmentary view in vertical section taken on the line 7-7 of Figure 3, and I Figure 8 is a fragmentary view in vertical section taken on the line 8'8 of Figure '5.

Referring to the drawings by numerals, 1 designates generally the pitman rod of'thisinvention and 3, 5 the upper and lower rod sections thereof respectively. The upper rod section 3 is designed for connection in any conventional manner, not shown, to the wind wheel 7 of the windmill 9 for operation by said wind wheel, whereas, the lower rod section 5 is bolted, as at 11, or otherwise suitably connected to the sucker rod 13 of the pump 15 of the windmill.

The rod sections 3, 5 are slidably connected together in longitudinal alignment by means of an elongated hollow sleeve 17 of rectangular cross-section depending 'through the front wall 25 from and suitably secured to the lower end of the upper rod section 3. As shown, the sleeves 17 may be secured to the upper'rod section 3 by'bolting thereto, as at 19, to the lower end of said rod section 3. The lower rod section 5 is slidably engaged in the sleeve 17. The sleeve 17 is sufiiciently long so that the upper rod section 3 may slide -on and relative to the lower rod section 5 during a complete cycle of reciprocation of the upper rod section 3 if the sucker rod 13 imposes an overload on the pitman rod 1.

The locking means for locking the upper and lower rod sections 3, 5 to each other and unlocking the same comprises a locking ball 21 extending through a tapered opening 23 in a front wall 25 of the sleeve 17 and seating under pressure in a front concave socket 27 in the lower rod section 5 registering with the opening 23. The locking ball 21 is confined in the opening 23 against vertical movement relative to the sleeve 17 when the locking ball 21 is seated so that the rod sections 3, 5 are locked to each other in the seated position of the locking ball 21.

The locking ball 21 is yieldingly retained seated in the socket 27 by means of an upright, spring loaded presser bar 29 in front of the sleeve 17 and the locking ball 21, said presser bar 29 having an apertured upper end 31 pivoted on a transverse bolt 32 projecting forwardly of the sleeve 17 with a nut 33 on said bolt 32 in front of said bar 29, the arrangement being such that the presser bar 29 is swingable toward and from the sleeve 17 and locking ball 21. A collar 35 on the bolt 32 between the presser bar 29 and the front sleeve wall 25 spaces said presser bar 29 from said front wall 25. An arcuate socket 37 in the lower end 39 of the presser bar 29 seats the locking ball 21 therein.

The presser bar 29 is spring loaded by means of a helical tension spring 41 in front thereof on a bolt 43 projecting forwardly through the front wall 25 of the sleeve 17 and through a slot 44 in an intermediate portion of the presser bar 29. The spring 41 is interposed between washers 45, 46 on the bolt 43. A nut 47 on the bolt 43 retains the spring 41 and the washers 45, 46 on the bolt 43. It is to be noted that the nut 47 provides for variably compressing the spring 41 to vary the pressure exerted against the presser bar 29 and the locking ball 21, for a purpose presently explained. Also, it is to be noted that the heads 49, 51 of the bolts 32, 43 are countersunk in the front wall 25 of the sleeve 17 to clear the interior of the sleeve 17, for an obvious reason, and apertures 53, 55 are provided in the back wall 57 of the sleeve 17 for inserting the bolts 32, 43 in place.

The operation of the invention as so far described is as follows. The locking ball 21 is normally seated in the socket 27 in locking position and yieldingly maintained seated by the presser bar 29, as shown in Figure 3, so that the upper and lower rod sections 3, 5 are normally locked to each other. If the pitman rod 1 is subjected to an overload by excessive dragging of the sucker rod 13 or freezing thereof, the upper rod section 3 will tend to move relative -to and independently of the lower 'rod section 5 and in response to such movement of the upper rod section 3, the locking ball 21 will be moved vertically relative to the socket 27 which will carn said ball 21 forwardly out of said socket 27 into unlocking position in opposition to the presser bar 29 to unlock the bar sections 3, 5 from each other all as shown in Figure 5. Then the upper rod section 3 may move independently of the lower rod section 5 to prevent breaking of the pitman rod 1. During such independent movement of the upper rod section 3, the sleeve 17 will slide on the lower rod section on the lower rod section 5.

assesso- By variably compressing the spring 41 through operation of the nut 47, the pressure of the presser bar 29 against the locking ball 21 may be varied, so that the locking ball 21 will move into unlocking position in response to; predetermine overloads onthe pitman rod 1, whereby the. unlocking will not occur by suddenacceleration of the Wind wheel 7 and pitman rod 1.

To prevent the locking ball 21 from repeatedlyseatingin the locking position during independent reciprocation. of the upper rod section 3, the following means is provided for locking the locking-ball in unseated unlocking;

position.

An upright elongated ball locking slide. plate 59 in. front of the front wall 25 of the sleeve 17 is mounted for vertical sliding movement on said wall 25 in transverse guides 60 on the Wall 25. The plate 59 is provided with longitudinal slots 61-, 63 therein straddling the bolts 32, 43, so that said bolts also guide said plate 59 in vertical movement of said plate.

The lockingslide plate59 is provided with a forked. lower yoke end 65 overlying and straddling and engagingthe locking ball 21'. A helical tension spring67 is termi nally secured to the spacing collar 35and to an upper endlug 68 on said plate 59, as at 69, 70 respectively, and. yieldingly urges said plate 59 downwardly and the forked end 65 of said plate 59 engaged with said locking ball.

The operation of the described ball locking means; is as,

follows. The forked end 65 ofsaid. plate 59, under the tension exerted bythe spring 67, yieldingly-engages the. locking ball '21 forwardly ofthe vertical center; of; said. ball 21, as shown in-Figuresii and 4, when said ball 21- is= seated, but, yieldingly engages said locking-ball 2-1arear.-. wardly of the vertical center of. said balk-21 when-the latter is-unseated and thereby lockssaid" locking'ball 21 in unseatedposition as shown in Figures-5,6 and 8;. As; the locking ball moves intounseated, unlocking position, it cams the lockingplate-59 upwardly inopposition to the spring a position such that the forked end 65 of said plate locks the ball in unseated unlocking position. Another lug 73 on the upper end of the plate59 provides'rneans for manually sliding said locking plate upwardly to unlock; the locking ball 21, when desired.

It is to be understood that the meansadescrihedherein for connecting rod sections together is susceptible of use 45- in substantially any machine for connecting rod'orshatt sectionsv together for disconnection underoverload pullerthrust thereon.

From the foregoing, the construction and. operation of? the device will be readilyunderstood and furtherexplanaa tion is believed to be unnecessary. However, since nu:

merous modifications and changes will readily occur to 1 those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and:

accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention as.

claimed.

What is claimed as new is as follows:

1. In combination, a windmill pitrnan rod comprising an upper rod section adapted to be connected to a wind wheel of a windmill, and a lower rod section adapted for com nection to apump, means on one red section slidably conq 67 which acts to slide the plate downwardly into-v for independent movement of one relative to the other, and

means on said first named means. for releasably holding said locking means unlocked throughout said independent movement.

2. The combinationof claim 1, said first named means comprising a terminal sleeve on one rodsection in which one end of. the other rod section is slidably fitted.

3. The combination of claim 2, said locking means comprising a socket in said one rod section, a ball extending through the sleeve and seating in the socket, said sleeve having an aperture therein through which said ball extends and is confined thereby against movement longitudinally of the sleeve, and spring loaded means on said sleeve engaging and yieldingly retaining said ball seated, said socket camming said ball into unseated position to unlock said rod sections inresponse to said overload.

4. The combination-of claim 3., said spring loaded means comprising a spring tensioned presser bar on said sleeve having a ball seating socket thereon.

5. In combination,v a windmill pitmanrod comprising an upper rod section. adapted to be connected to a wind wheelof a windmill, and a lower .rodsection adapted for connectionto a-vpurnp, means on one rod section slidably connecting said rod 'sectionstogether in alignment for relative movement longitudinally, locking means on said.

first,namedmeans'and one rod section locking saidsections.-.-toge ther for. movement in unison andoperative: in response, to overloadon the .pitman-rod to'unloclc said rod by against movement longitudinally of the sleeve, and

springloaded means on said sleeve engaging and yieldingly: retaining said ball seated, said socket carnming said ball into unseated position to unlock said rod sections in.

response to'said overload, said means-for releasably holding said-"lockingmeans'comprising a forked slide plate on said sleeve springloaded and engaging and straddling said balL.

References Cited inth'efile of this patent' UNITED STATES PATENTS 136,690v Aufdernbrinke Mar. 11, 1873 595,484: Klo'pfenstein Dec. 14, 1897 '1',l3'l,1'6 l' Root Mar. 9, 1915 1,298,567 Root Mar. 25, 1919 2,229,473 Redmer' Jan. 21, 1941 2,391,682 Cramer Dec. 25, 1945 2;497,3l9' Mott Feb. 14, 1950 2,516,642 Murphy, July25, 1950 2,711,918 Benson June.28,.1955

the sleeve and 

